From c1d5a012ea4b824e902db14e47bf147d727c2657 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Fri, 20 Oct 2023 13:35:49 +0200
Subject: [PATCH] core/state, tests: fix memory leak via fastcache (#28387)

This change fixes a memory leak, when running either state-tests or blockchain-tests, we allocate a `1MB` fastcache during snapshot generation. `fastcache` is a bit special, and requires a `Reset()` (it has it's own memory allocator).

The `1MB` was hidden [here](https://github.com/ethereum/go-ethereum/blob/master/tests/state_test_util.go#L333) and [here](https://github.com/ethereum/go-ethereum/blob/master/tests/block_test_util.go#L146) respectively.
---
 appveyor.yml                     |  2 +-
 build/ci.go                      |  4 ++++
 core/blockchain.go               |  1 +
 core/state/snapshot/disklayer.go | 10 ++++++++++
 core/state/snapshot/snapshot.go  |  7 +++++++
 tests/state_test_util.go         |  3 +++
 6 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/appveyor.yml b/appveyor.yml
index 114aec644..4a8c4b737 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -54,4 +54,4 @@ for:
       - go run build/ci.go archive -arch %GETH_ARCH% -type zip -signer WINDOWS_SIGNING_KEY -upload gethstore/builds
       - go run build/ci.go nsis -arch %GETH_ARCH% -signer WINDOWS_SIGNING_KEY -upload gethstore/builds
     test_script:
-      - go run build/ci.go test -dlgo -arch %GETH_ARCH% -cc %GETH_CC%
+      - go run build/ci.go test -dlgo -arch %GETH_ARCH% -cc %GETH_CC% -short
diff --git a/build/ci.go b/build/ci.go
index 1ff3fb5bf..46f1ac281 100644
--- a/build/ci.go
+++ b/build/ci.go
@@ -285,6 +285,7 @@ func doTest(cmdline []string) {
 		coverage = flag.Bool("coverage", false, "Whether to record code coverage")
 		verbose  = flag.Bool("v", false, "Whether to log verbosely")
 		race     = flag.Bool("race", false, "Execute the race detector")
+		short     = flag.Bool("short", false, "Pass the 'short'-flag to go test")
 		cachedir = flag.String("cachedir", "./build/cache", "directory for caching downloads")
 	)
 	flag.CommandLine.Parse(cmdline)
@@ -318,6 +319,9 @@ func doTest(cmdline []string) {
 	if *race {
 		gotest.Args = append(gotest.Args, "-race")
 	}
+	if *short {
+		gotest.Args = append(gotest.Args, "-short")
+	}
 
 	packages := []string{"./..."}
 	if len(flag.CommandLine.Args()) > 0 {
diff --git a/core/blockchain.go b/core/blockchain.go
index baf2f9f82..fc5c249ce 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -989,6 +989,7 @@ func (bc *BlockChain) Stop() {
 		if snapBase, err = bc.snaps.Journal(bc.CurrentBlock().Root); err != nil {
 			log.Error("Failed to journal state snapshot", "err", err)
 		}
+		bc.snaps.Release()
 	}
 	if bc.triedb.Scheme() == rawdb.PathScheme {
 		// Ensure that the in-memory trie nodes are journaled to disk properly.
diff --git a/core/state/snapshot/disklayer.go b/core/state/snapshot/disklayer.go
index 513f0f5ab..d563b67ca 100644
--- a/core/state/snapshot/disklayer.go
+++ b/core/state/snapshot/disklayer.go
@@ -45,6 +45,16 @@ type diskLayer struct {
 	lock sync.RWMutex
 }
 
+// Release releases underlying resources; specifically the fastcache requires
+// Reset() in order to not leak memory.
+// OBS: It does not invoke Close on the diskdb
+func (dl *diskLayer) Release() error {
+	if dl.cache != nil {
+		dl.cache.Reset()
+	}
+	return nil
+}
+
 // Root returns  root hash for which this snapshot was made.
 func (dl *diskLayer) Root() common.Hash {
 	return dl.root
diff --git a/core/state/snapshot/snapshot.go b/core/state/snapshot/snapshot.go
index e30a0005c..638984238 100644
--- a/core/state/snapshot/snapshot.go
+++ b/core/state/snapshot/snapshot.go
@@ -656,6 +656,13 @@ func diffToDisk(bottom *diffLayer) *diskLayer {
 	return res
 }
 
+// Release releases resources
+func (t *Tree) Release() {
+	if dl := t.disklayer(); dl != nil {
+		dl.Release()
+	}
+}
+
 // Journal commits an entire diff hierarchy to disk into a single journal entry.
 // This is meant to be used during shutdown to persist the snapshot without
 // flattening everything down (bad for reorgs).
diff --git a/tests/state_test_util.go b/tests/state_test_util.go
index 8c255c1b5..745a3c6b2 100644
--- a/tests/state_test_util.go
+++ b/tests/state_test_util.go
@@ -200,6 +200,9 @@ func (t *StateTest) Run(subtest StateSubtest, vmconfig vm.Config, snapshotter bo
 		if triedb != nil {
 			triedb.Close()
 		}
+		if snaps != nil {
+			snaps.Release()
+		}
 	}()
 	checkedErr := t.checkError(subtest, err)
 	if checkedErr != nil {